This invention relates generally to a housing with an aperture through which extends an electrical conductor and is particularly directed to strain relief for an electrical conductor extending from a connector housing.
With each end of an electrical lead coupled to a respective circuit, the lead frequently extends through an aperture in a housing within which one of the circuits is disposed. The electrical lead may include a single conductor or a plurality of conductors either in the form of a flat ribbon cable or in the form of a twisted, multi-strand cable. Whatever the form of the cable, it is frequently subject to bending distortion as it exits the enclosure or housing containing circuitry to which one end of the cable is connected. Repeated and continuous bending of the cable will eventually result in damage to and possibly breaking of either the electrical conductor, or conductors, or the insulating sheath encapsulating the conductor. This damage is caused by bending the cable to angular displacements which exceed the flexibility limitations of the insulation and/or conductor as well as contact between the cable and the edges of the housing defining the aperture through which the cable extends. In either case, bending of the cable over an extended period will result in a weakening of the cable, exposure of the conductors within the cable, and possibly breakage of the cable including the conductors therein.
In addressing this problem, the prior art has relied primarily upon the use of heat shrink tubing disposed about the cable as it transits an aperture in the housing. The heat shrink tubing protects the cable from abrasion caused by rubbing against the edges of the panel defining the aperture. The relative stiffness of the tubing also limits the radius of curvature to which the cable may be bent for reducing the possibility of "kinking" the cable resulting in possible exposure and breakage of the conductors within the cable. However, the use of heat shrink tubing around the cable increases the cost and complexity of the cable installation and thus has only limited commercial appeal. Moreover, the heat shrink tubing itself is subject to permanent distortion and breakage arising from extensive bending action over an extended period and thus offers only limited protection for the electrical conductors and their outer insulating sheath.
The present invention provides strain relief for an electrical cable which does not suffer from the limitations of the prior art through the use of a uniquely configured surface of a panel positioned immediately adjacent to an aperture through which the cable passes so as to limit the angular displacement to which the cable may be bent. The strain relief arrangement of the present invention also provides protection for the cable from excessive pulling forces using an inexpensive, easily fabricated and assembled, and highly reliable cable installation arrangement.